:root{--accent: #3568ec;--accent-soft: #eef3ff;--text: #1f2329;--text-muted: #8a919f;--border: #e8eaef;--bg: #f5f6f8;--topbar-h: 56px}*{box-sizing:border-box;margin:0;padding:0}html,body,#app{height:100%}body{font-family:-apple-system,BlinkMacSystemFont,PingFang SC,Microsoft YaHei,Helvetica Neue,sans-serif;color:var(--text);background:var(--bg);-webkit-font-smoothing:antialiased}.shell{display:flex;flex-direction:column;height:100%}.topbar{flex:none;display:flex;align-items:center;gap:24px;height:var(--topbar-h);padding:0 20px;background:#fff;border-bottom:1px solid var(--border);padding-top:env(safe-area-inset-top);box-sizing:content-box}.brand{display:flex;align-items:center;gap:10px;min-width:0}.logo{width:30px;height:30px;border-radius:9px;background:linear-gradient(135deg,var(--accent),#6b8cff);color:#fff;font-size:15px;font-weight:700;display:grid;place-items:center;flex:none}.brand-name{font-size:16px;font-weight:600;white-space:nowrap}.tabs{display:flex;gap:4px;padding:4px;border-radius:10px;background:var(--bg)}.tab{display:flex;align-items:center;gap:6px;padding:7px 16px;border:0;border-radius:8px;background:transparent;color:var(--text-muted);font-size:14px;font-family:inherit;cursor:pointer;transition:background .15s,color .15s}.tab:hover{color:var(--text)}.tab.active{background:#fff;color:var(--accent);font-weight:600;box-shadow:0 1px 3px #141e3c14}.tab-icon{display:inline-flex;width:15px;height:15px}.tab-icon svg{width:100%;height:100%}.user{margin-left:auto;display:flex;align-items:center;gap:14px;font-size:13px}.user-name{font-weight:500;white-space:nowrap}.user-name.muted{color:var(--text-muted);font-weight:400}.link{border:0;background:none;color:var(--text-muted);font-size:13px;font-family:inherit;text-decoration:none;cursor:pointer;white-space:nowrap}.link:hover{color:var(--accent)}.stage{position:relative;flex:1;min-height:0}.frame{position:absolute;top:0;right:0;bottom:0;left:0;width:100%;height:100%;border:0;background:#fff}.canvas-hint{position:absolute;top:12px;left:50%;transform:translate(-50%);z-index:10;display:flex;align-items:center;gap:12px;max-width:calc(100% - 32px);padding:10px 14px;border-radius:10px;background:#1f2329eb;color:#fff;font-size:13px;box-shadow:0 6px 20px #0000002e}.canvas-hint button{border:0;border-radius:6px;padding:4px 10px;background:#ffffff2e;color:#fff;font-size:12px;font-family:inherit;cursor:pointer;flex:none}.shell.mobile{--topbar-h: 50px}.shell.mobile .topbar{gap:10px;padding:0 12px}.shell.mobile .brand-name{display:none}.shell.mobile .tabs{flex:1;justify-content:center}.shell.mobile .tab{flex:1;justify-content:center;padding:7px 8px;font-size:13px}.shell.mobile .user .link{display:none}.shell.mobile .user{gap:0}.shell.mobile .user-name{max-width:64px;overflow:hidden;text-overflow:ellipsis}